It was recognized by the present inventor that there is a need for an improved human powered propulsion device for a small boat, particularly a pedal driven outboard motor that is readily removably mountable to a canoe.
Various known types of human powered propulsion devices for water craft include those which are attachable to the transom of a boat and are pedal driven or operated by hand. Several devices employ various linkages, steering devices, drives and shaft mechanisms to accomplish the task of propelling a watercraft such as a small boat or canoe. Many of such devices rely on complicated mechanisms and cumbersome shafts and structures which interfere with operator comfort while others require that the hull of a boat be penetrated to accommodate such devices. Such known propulsion devices are inconvenient and dangerous to use. Many human powered propulsion are unsuitable for removably mounting on the gunwales of a canoe, for example. Others are not portable and are not readily disassembled for transporting or for storage.
U.S. Pat. No. 4,891,024 to Benjamin, shows a pedal boat propulsion system attachable to the transom of a boat with a pedal crank assembly having communicating shafts and U.S. Pat. No. 4,943,251 to Lerach et al shows a pedal operated drive system for a canoe with a series of rods and drive shafts with a pedal crank assembly disposed in a manner similar to Benjamin. A disadvantage of the inventions disclosed by both Benjamin and Lerach et al is that they both have long shafts located within the hull of the craft extending longitudinally from stern to bow which consumes valuable interior space for occupants or equipment.
U.S. Pat. No. 5,030,145 to Chase shows a manually operable boat propeller which operates via a hand operated single handle for driving, steering and tilting the removably mountable unit and U.S. Pat. No. 2,956,535 to Hunt discloses a manual single handle propelling and steering apparatus for small boats using a bicycle-like sprocket and chain arrangement for operation. A major disadvantage of the inventions of both Chase nor Hunt is that using the hands for propulsion is inconvenient, for example, during fishing or when eating or drinking and is very fatiguing. Furthermore, the devices of both Chase and Hunt could not be used on the gunwales of a canoe.
U.S. Pat. No. 4,676,755 to Yagan shows a removably attachable pedal driven device with a flexible drive shaft for a canoe and for a surfboard. A disadvantage of this invention is that it is not readily adaptable to any canoe without extensive modification such as by cutting a hole in the hull of the canoe for accommodating the flexible drive shaft and later, plugging the hole with a hatch. This design is undesirable due to the danger of the potential for water leakage.
U.S. Pat. No.4,427,392 to Schneider shows an outboard propeller drive and steering assembly for a boat with a bicycle-type driving system. A disadvantage of the device of Schneider is that valuable interior space for occupants or equipment is reduced due to the interior placement of the propulsion mechanisms within the hull of the boat.
U.S. Pat. No. 4,324,551 to Gurries shows a bow mounted propeller driven boat with foot actuated pedals for maneuvering and is powered by operating the hand cranks. A disadvantage of this device is that the hands must be used to power and propel the boat which could be very difficult especially in adverse conditions or in a relatively swift current. Also, relying also upon the feet to maneuver the boat can further contribute to operator fatigue. The device is not suited for removably mounting on the gunwales of the boat.
U.S. Pat. No. 3,987,749 to Anderson shows a pedal operated propulsion unit for a small boat. The disadvantage of this design is as previously mentioned, in that the hull of the boat must be penetrated for installation thereby subjecting it to the danger of the potential for water leakage.
U.S. Pat. No. 5,282,762 to Cerreto shows a complicated mechanism for a pedal operated water craft.
Accordingly, it becomes clear that there is a great need for a pedal driven propulsion device for watercraft such as a human powered outboard motor device with a drive linkage and a steering assembly for propelling and for steering a boat such as a canoe which overcomes the disadvantages of the prior art human powered propulsion devices. Such a propulsion device should be one that is easy to use, is readily removably mountable on a canoe with no structural modifications, is fun and healthful to use and is economically manufactured.